STM32W108CBU6 STMICROELECTRONICS [STMicroelectronics], STM32W108CBU6 Datasheet - Page 39

• Manufacturer Part Number: STM32W108CBU6
• Description: High-performance, IEEE 802.15.4 wireless system-on-chip
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

STM32W108CB, STM32W108HB
5.3.1
Figure 6
shows all the clock sources and the general areas of the chip to which they are routed.
Figure 6.
High-frequency internal RC oscillator (OSCHF)
The high-frequency RC oscillator (OSCHF) is used as the default system clock source when
power is applied to the core domain. The nominal frequency coming out of reset is 12 MHz.
Most peripherals, excluding the radio peripheral, are fully functional using the OSCHF clock
source. Application software must be aware that peripherals are clocked at different speeds
depending on whether OSCHF or OSC24M is being used. Since the frequency step of
OSCHF is 0.5 MHz and the high-frequency crystal oscillator is used for calibration, the
calibrated accuracy of OSCHF is +/-250 kHz +/-40 ppm. The UART and ADC peripherals
may not be usable due to the lower accuracy of the OSCHF frequency.
shows a block diagram of the clocks in the STM32W108. This simplified view
Clocks block diagram
Doc ID 16252 Rev 2
System modules
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